A known electrophotographic image forming apparatus includes a main body having an opening, an LED head, and a photosensitive member unit integrally including a photosensitive drum and a toner cartridge. The photosensitive member unit is configured to be detachably attachable to the main body through the opening. The LED head is configured to expose the photosensitive drum.
The main body includes a top cover to open and close the opening. The LED head is held on an inner surface of the top cover.
When the top cover is in a closed position to close the opening, the LED head is brought close to the photosensitive drum. When the top cover is in an open position to release the opening, the LED head is separated from the photosensitive drum.
Before the photosensitive member unit is attached to or removed from the main body, the top cover is located in the open position so that the LED head is separated from the photosensitive drum.